Does cinnamon lower blood pressure?

Possibly by a few points, mostly in people with type 2 diabetes or metabolic syndrome, and nobody can yet say by how much. A 2020 meta-analysis of 9 trials in 641 adults found cinnamon supplements lowered systolic pressure by 6.23 mm Hg (95% CI 1.77 to 10.69). A 2021 meta-analysis of 8 trials in 582 adults found systolic pressure did not change. The newest review, of 49 trials in 2025, found a fall and rated the certainty of the evidence very low.

Unsettled. The reviews agree on the direction more often than not and disagree on the size. They pool small, short trials of capsules, most of them in people with diabetes, and most trials do not say whether the cinnamon was cassia or Ceylon. In the 2025 review the systolic result lost statistical significance when a single trial was taken out. In the only trial in this set with blood pressure as its main aim, the fall was no longer linked to cinnamon once each person's starting pressure was allowed for.

What the trials found

The pooled analyses

Two 2020 meta-analyses drew on the same 9 trials and 641 people. The first found systolic pressure fell by 6.23 mm Hg and diastolic by 3.93 (95% CI 1.52 to 6.33). The second found falls of 5.17 and 3.36 mm Hg overall, and in its subgroups the fall held only in trials that used 2 g a day or less, ran beyond 8 weeks and enrolled people with a BMI of 30 or more. Its authors note that few participants had high blood pressure. The 2021 meta-analysis, from a similar pool of 8 trials, found a systolic change of -0.61 mm Hg (95% CI -1.36 to 0.14) that did not reach significance. Its abstract also reports a diastolic fall of 0.93 mm Hg.

In people with metabolic diseases, a 2022 dose-response meta-analysis of 35 trials found falls of 3.95 mm Hg systolic and 3.36 diastolic, with no confidence interval in its abstract and blood pressure as a secondary outcome. In type 2 diabetes, a 2020 meta-analysis of 9 trials reported the effect only on a standardized scale, -0.53 for systolic pressure with an interval reaching -0.03, close to no effect. A 2024 umbrella review of meta-analyses put the effect at 2.36 mm Hg systolic and 1.65 diastolic.

The 2025 meta-analysis is the largest, with 49 trials searched to July 2024, and the only one we read in full. It found standardized falls of -0.85 for systolic and -1.04 for diastolic pressure, with heterogeneity of 94.3 and 88.6 percent, so the trials disagreed sharply. Without one trial the systolic result became -0.61 (95% CI -1.27 to 0.04) and lost significance. The diastolic result held. The authors graded the certainty very low for both.

Single trials

In a 12-week UK trial in 58 people with poorly controlled type 2 diabetes, 2 g of cinnamon a day took blood pressure from 132.6/85.2 to 129.2/80.2 mm Hg, while the placebo group stayed near 134.5/86.8. In a 12-week trial in 59 adults with type 2 diabetes on 1200 mg a day, systolic pressure fell 3.4 mm Hg on cinnamon and rose 1.9 on placebo (P = .06). Once the authors allowed for where each person started, the difference was no longer linked to treatment. That is the only trial in this set with blood pressure as its main aim.

In 116 Asian Indians with metabolic syndrome, 3 g a day in capsules for 16 weeks improved blood pressure along with waist-hip ratio and blood fats, and the abstract gives no size for the blood pressure change. When 204 people with type 2 diabetes took 3 g a day in black tea for 8 weeks, blood pressure did not change differently from tea alone. That dose in a drink is the one closest to how people use the spice.

Who should be careful

Across 7 randomized trials, cinnamon supplements did not change the liver enzymes ALT, AST or ALP in adults. Those trials were short and did not separate the species, so they do not rule out the rare liver injury from high-coumarin cassia products that case reports describe. A review of adverse events found that only 5 of 38 clinical trials reported any, mostly stomach upsets and allergic reactions, and its authors judged that larger doses or longer use as a medicine should be clinically monitored.

Not for everyone. Cassia, the cheaper and commoner cinnamon, contains coumarin, which has been linked to liver problems. The US National Center for Complementary and Integrative Health says ordinary cassia use does not usually supply enough coumarin to cause significant problems, and some cassia products carry high levels. Ceylon cinnamon has only traces. Food is no shield here. In 24 healthy volunteers, coumarin was absorbed from cinnamon in rice pudding at 54.7 percent and from cinnamon tea at 66.1, against 62.8 percent from an isolated coumarin capsule. If you have liver disease, take a cassia supplement only after talking it over with your doctor.

In pregnancy, the same agency says cinnamon in amounts found in food appears safe, and larger amounts of Ceylon cinnamon are considered unsafe. We found no trial of cinnamon and blood pressure in pregnancy or in children. Most trials above enrolled people with type 2 diabetes, and the UK trial enrolled only people on diabetes tablets. If you take medicine for blood pressure or blood sugar, a supplement is a conversation with whoever prescribes it.

What expert bodies say

The US National Center for Complementary and Integrative Health, in a page updated in 2024, says research does not clearly support using cinnamon for any health condition, and it does not mention blood pressure. We found no blood pressure guideline that recommends cinnamon.

How we searched

What would change this answer

• A trial large enough to answer the question in adults with diagnosed high blood pressure, with 24-hour ambulatory readings and a run of 6 months or more. No trial in this set ran longer than 16 weeks, and none is registered on ClinicalTrials.gov.
• Trials that name the species and measure the coumarin in what they give, so that benefit and liver risk can be weighed for the same product.
• Any data on heart attacks or strokes. Every result here is a reading on a cuff.
• Any data in pregnancy and in children.

What cinnamon contains and the rest of its evidence is on the cinnamon page.

Sources

1. ev-cinbp-01 · Meta-analysis or systematic review · systematic review and dose-response meta-analysis of randomized controlled trials · n = 641
   Cinnamon supplementation resulted in significant reduction in SBP (Weighted Mean Differences (WMD): -6.23 mmHg, 95% CI: -10.69 to -1.77, P = 0.006) and DBP (WMD: -3.93 mmHg, 95% CI: -6.33 to -1.52, P = 0.001).
   
   Who: Adults in randomized clinical trials of oral cinnamon supplementation
   Effect: SBP -6.23 mm Hg (95% CI -10.69 to -1.77); DBP -3.93 mm Hg (95% CI -6.33 to -1.52); larger SBP fall with 2 g or less, 12 weeks or more, age under 50
   Certainty: Wide CI; small trials mostly in type 2 diabetes; no non-linear dose or duration relation; species rarely stated.
   Crit Rev Food Sci Nutr, 2020 · checked 2026-10-07 · we read the abstract
2. ev-cinbp-02 · Meta-analysis or systematic review · systematic review and meta-analysis of randomized controlled trials · n = 641
   Meta-analysis of 9 RCTs with 641 participants showed significant reductions in both systolic (WMD: -5.17 mmHg, 95% CI: -9.35 to -0.99, P = 0.01) and diastolic blood pressure (WMD: -3.36 mmHg, 95% CI: -5.67 to -1.04, P ≤ 0.001) after cinnamon supplementation.
   
   Who: Adults in 9 RCTs of cinnamon supplementation
   Effect: SBP -5.17 mm Hg (95% CI -9.35 to -0.99); DBP -3.36 mm Hg (95% CI -5.67 to -1.04); significant only at <=2 g/day, >8 weeks, baseline BMI >=30
   Certainty: Same trial pool as 31617744; the authors note few hypertensive participants and small samples.
   Clin Nutr ESPEN, 2020 · checked 2026-10-07 · we read the abstract
3. ev-cinbp-03 · Meta-analysis or systematic review · systematic review and meta-analysis of randomized controlled trials · n = 582
   The pooled effect size showed that SBP did not change following cinnamon supplementation. (WMD: -0.61mmHg; 95% CI: -1.36, 0.14, P= 0.111).
   
   Who: Adults in 8 RCTs using cinnamon supplements
   Effect: SBP -0.61 mm Hg (95% CI -1.36 to 0.14, not significant); SBP -1.25 mm Hg in trials of 8 weeks or more; DBP -0.93 mm Hg (95% CI -1.55 to -0.32)
   Certainty: Disagrees with 31617744 and 32220351 on size, from a similar trial pool; the gap shows how unstable the pooled estimate is.
   Endocr Metab Immune Disord Drug Targets, 2021 · checked 2026-10-07 · we read the abstract
4. ev-cinbp-04 · Meta-analysis or systematic review · systematic review and dose-response meta-analysis of randomized controlled trials · n = 35 trials
   Also, our findings of the present meta-analysis showed that cinnamon supplementation could have favorable effects on high density lipoprotein-cholesterol (HDL-C, WMD = 1.35; P = 0.038) as well as systolic (WMD = -3.95 mmHg; P = 0.018) and diastolic (WMD = -3.36; P = 0.001) blood pressure among patients with metabolic diseases.
   
   Who: Patients with metabolic diseases in 35 clinical trials
   Effect: SBP WMD -3.95 mm Hg (P = 0.018); DBP WMD -3.36 mm Hg (P = 0.001)
   Certainty: BP was a secondary outcome; abstract gives no CI for BP; search to January 2020.
   Crit Rev Food Sci Nutr, 2022 · checked 2026-10-07 · we read the abstract
5. ev-cinbp-05 · Meta-analysis or systematic review · systematic review and meta-analysis of clinical trials · n = 9 trials
   This meta-analysis found a significant reduction in systolic blood pressure (SBP) (SMD: -0.532, 95% CI: [-1.032, -0.033], P = 0.037) and diastolic blood pressure (DBP) (SMD: -0.681, 95% CI: [-1.297, -0.065], P = 0.030) of patients with type 2 diabetes following cinnamon supplementation.
   
   Who: Patients with type 2 diabetes
   Effect: SBP SMD -0.53 (95% CI -1.03 to -0.03); DBP SMD -0.68 (95% CI -1.30 to -0.07); no significant change in weight or BMI
   Certainty: Standardized mean difference, so no mm Hg figure; upper CI close to zero.
   Diabetes Metab Syndr, 2020 · checked 2026-10-07 · we read the abstract
6. ev-cinbp-06 · Meta-analysis or systematic review · umbrella review of meta-analyses of randomized controlled trials, PROSPERO CRD42023487350 · n = —
   The findings revealed that cinnamon might exert favorable effects on systolic blood pressure (SBP) (ES = -2.36 mmHg; 95% CI: 3.86, -1.40), diastolic blood pressure (DBP) (ES = -1.65 mmHg; 95% CI: 2.41, -0.90), total antioxidant capacity (TAC) (WMD = 0.34; 95% CI: 0.04, 0.64), and interleukin-6 (IL-6) (WMD = -1.48; 95% CI: 2.96, -0.01).
   
   Who: Adults in meta-analyses of randomized clinical trials of cinnamon
   Effect: SBP ES -2.36 mm Hg; DBP ES -1.65 mm Hg
   Certainty: The CIs printed in the abstract have lost their minus signs; the authors cite limited studies and clinical diversity.
   Nutr Metab Cardiovasc Dis, 2024 · checked 2026-10-07 · we read the abstract
7. ev-cinbp-07 · Meta-analysis or systematic review · GRADE-assessed systematic review, dose-response and meta-analysis of randomized controlled trials · n = 49 trials
   Sensitivity analyses for DBP confirmed stable outcomes, while excluding Al Daheri et al. [70] significantly altered the SBP results (SMD: − 0.61; 95% CI: − 1.27, 0.04).
   
   Who: Adults in randomized controlled trials of cinnamon, search to July 2024
   Effect: DBP SMD -1.04 (95% CI -1.54 to -0.55), I2 88.6%; SBP SMD -0.85 (95% CI -1.54 to -0.16), I2 94.3%; SBP without Al Daheri et al. SMD -0.61 (95% CI -1.27 to 0.04); GRADE very low
   Certainty: Very high heterogeneity; GRADE very low for both SBP and DBP (Table 4).
   Journal of Health, Population and Nutrition, 2025 (Jafari et al.) · checked 2026-10-07 · we read the fulltext
8. ev-cinbp-08 · Randomized controlled trial(s) · randomized placebo-controlled double-blind clinical trial, 12 weeks · n = 58
   Mean systolic and diastolic blood pressures (SBP and DBP) were also significantly reduced (P<0.001) after 12 weeks in the cinnamon group (SBP: 132.6 to 129.2 mmHg and DBP: 85.2 to 80.2 mmHg) compared with the placebo group (SBP: 134.5 to 134.9 mmHg and DBP: 86.8 to 86.1 mmHg).
   
   Who: 58 type 2 diabetic patients aged 54.9, on hypoglycemic agents only, HbA1c above 7%
   Effect: cinnamon SBP 132.6 to 129.2, DBP 85.2 to 80.2 mm Hg; placebo SBP 134.5 to 134.9, DBP 86.8 to 86.1 mm Hg (P < 0.001)
   Certainty: Single small trial; species of cinnamon not stated in the abstract.
   Diabet Med, 2010 · checked 2026-10-07 · we read the abstract
9. ev-cinbp-09 · Randomized controlled trial(s) · randomized placebo-controlled trial, 12 weeks · n = 59
   However, when baseline SBP was included in the model as a covariate, change from baseline SBP was no longer associated with treatment.
   
   Who: Adult subjects 30 years of age or older with type 2 diabetes, mean age 63
   Effect: SBP -3.4 +/- 11.4 mm Hg on cinnamon vs +1.9 +/- 10.2 mm Hg on placebo (P = .06); no treatment effect after adjusting for baseline SBP
   Certainty: Small, but the only trial with BP as its primary aim; shows how baseline imbalance can create an apparent effect.
   J Med Food, 2011 · checked 2026-10-07 · we read the abstract
10. ev-cinbp-10 · Randomized controlled trial(s) · randomized double-blind controlled trial, 16 weeks, 3 g cinnamon in 6 capsules daily · n = 116
    Other parameters which showed significantly greater improvement were: waist-hip ratio, blood pressure, serum total cholesterol, low-density lipoprotein cholesterol, serum triglycerides, and high-density lipoprotein cholesterol.
    
    Who: 116 individuals with metabolic syndrome, north India
    Effect: significantly greater improvement in blood pressure vs placebo (size not given in abstract); metabolic syndrome prevalence fell 34.5% vs 5.2%
    Certainty: Retrospectively registered (NCT02455778); BP size not reported in the abstract; full text not in local PMC.
    Lipids Health Dis, 2017 · checked 2026-10-07 · we read the abstract
11. ev-cinbp-11 · Randomized controlled trial(s) · randomized controlled clinical trial, 5 arms, 8 weeks · n = 204
    No significant difference was found between various medicinal plants in terms of influencing BP, serum soluble (s)ICAM-1 concentrations and anthropometric measures.
    
    Who: 204 T2DM patients in five groups: cinnamon, cardamom, saffron, ginger, or tea only
    Effect: no significant difference between groups in SBP, DBP or sICAM-1 after 8 weeks
    Certainty: About 40 per arm; cinnamon given as a food-like dose in tea, closer to kitchen use than capsules.
    Blood Press, 2016 · checked 2026-10-07 · we read the abstract
12. ev-cinbp-12 · Meta-analysis or systematic review · systematic review and meta-analysis of randomized controlled trials · n = 7 trials
    In summary, cinnamon supplementation had no significant effect on liver enzymes in adults.
    
    Who: Adults in 7 RCTs (9 treatment arms) of cinnamon supplementation
    Effect: no significant effect on AST, ALT or ALP; ALT lower at <1500 mg/day and in trials >12 weeks (Hedges g -0.61 and -0.83)
    Certainty: Short trials, species not separated; does not rule out rare coumarin liver injury from cassia products, which case reports describe.
    Complement Ther Med, 2021 · checked 2026-10-07 · we read the abstract
13. ev-cinbp-13 · Position of an expert body · agency web page · n = —
    Consuming cassia cinnamon doesn’t usually include enough coumarin to cause significant problems; however, some cassia cinnamon products contain high levels of coumarin.
    
    Who: general population; people with liver disease
    Effect: coumarin-liver interactions reported; risk mainly with high-coumarin cassia products and prolonged use
    Certainty: Two requests: WebFetch of the NCCIH page and an independent curl of the same page returned the same wording.
    NIH National Center for Complementary and Integrative Health, Cinnamon: Usefulness and Safety, updated November 2024 · checked 2026-10-07 · we read the page
14. ev-cinbp-14 · Position of an expert body · agency web page · n = —
    Some studies of the use of Ceylon and cassia cinnamon during pregnancy suggest it is safe in amounts commonly found in foods, but Ceylon cinnamon in larger amounts during pregnancy is considered unsafe.
    
    Who: pregnant people
    Effect: food amounts likely safe; larger supplemental amounts of Ceylon cinnamon considered unsafe in pregnancy
    Certainty: Two requests: WebFetch of the NCCIH page and an independent curl of the same page returned the same wording.
    NIH National Center for Complementary and Integrative Health, Cinnamon: Usefulness and Safety, updated November 2024 · checked 2026-10-07 · we read the page
15. ev-cinbp-15 · Position of an expert body · agency web page · n = —
    Research doesn’t clearly support using cinnamon for any health condition.
    
    Who: general population
    Effect: no endorsed health use, blood pressure not mentioned
    Certainty: Two requests: WebFetch of the NCCIH page and an independent curl of the same page returned the same wording.
    NIH National Center for Complementary and Integrative Health, Cinnamon: Usefulness and Safety, updated November 2024 · checked 2026-10-07 · we read the page
16. cin-r2-03 · Randomized controlled trial(s) · four-way crossover controlled trial giving the same 12 mg dose of coumarin in four forms, isolated coumarin in a capsule as reference, cassia cinnamon in capsules, cinnamon tea and cinnamon in rice pudding, with relative absorption measured as urinary excretion of the metabolite 7-hydroxycoumarin over 8 hours and plasma levels over 105 minutes · n = 24
    The relative extent of absorption measured as urinary excretion of the main metabolite 7-hydroxycoumarin (7OHC) was found to be 62.8% for isolated coumarin in a capsule (reference), 56.0% for cinnamon in capsules, 66.1% for cinnamon tea, and 54.7% for cinnamon in rice pudding (means, n=23, observation period 8 hours).
    
    Who: 24 healthy volunteers, 23 analyzed
    Effect: relative absorption was 62.8% for isolated coumarin, 56.0% for cinnamon in capsules, 66.1% for cinnamon tea and 54.7% for cinnamon in rice pudding; tea gave the fastest absorption and the highest peak plasma concentration; the authors conclude the tolerable daily intake for coumarin can be applied to coumarin exposure from cinnamon-containing meals
    Certainty: 24 people, one dose, and a 2011 study, but it answers a question that is usually waved away rather than tested. What it does not do is tell you how much coumarin is in any particular jar: cassia carries up to about 1% and Ceylon cinnamon almost none, and shop labels rarely say which one it is. We do not publish the tolerable daily intake figure itself here because no source we could reach verified it
    Mol Nutr Food Res, 2011 · checked 2026-09-22 · we read the abstract
17. cin-r2-04 · Observational data · systematic review of human adverse event reports, Medline, Scopus, ScienceDirect, Embase, PubMed Central and Google Scholar searched for the terms cinnamon and cinnamomum across clinical trials, case reports and case series, plus spontaneous reports collected from five national and international reporting schemes · n = —
    The available data suggests that despite the safety of cinnamon use as a spice and/or flavoring agent, its use may be associated with significant adverse effects in medicinal uses with larger doses or longer duration of use and should be clinically monitored.
    
    Who: 38 clinical trials, 20 case reports, 7 case series and 160 spontaneous adverse event reports
    Effect: only 5 of the 38 clinical trials reported adverse events at all; the most frequent were gastrointestinal disorders and allergic reactions, self-limiting in the majority of cases
    Certainty: spontaneous reporting counts what somebody bothered to report, so this gives no rate and misses slow harms entirely. That 33 of 38 trials reported no adverse events is as likely to reflect trials not asking as cinnamon not causing. The distinction the authors draw between culinary and medicinal use is the line worth carrying, because the trials in this file all used the medicinal dose
    Clin Nutr, 2019 · checked 2026-09-22 · we read the abstract